In recent years, examples that use a centrifugal blood pump device that use magnetic coupling to transmit drive torque of an external motor to an impeller within a blood chamber has increased as a blood circulation device of an artificial heart lung device. With this centrifugal blood pump device, physical communication between the blood chamber and the outside can be eliminated thereby preventing the introduction of bacteria and the like into the blood.
A centrifugal blood pump of Japanese Unexamined Patent Application Publication No. 2004-209240 (Patent Document 1) is provided with a housing including a first to a third chamber divided by first and second barrier walls, an impeller rotatably provided in the second chamber (blood chamber), a magnetic body provided on one side face of the impeller, an electrical magnet provided in the first chamber opposing one side face of the impeller, a permanent magnet provided on the other side face of the impeller, a rotor and a motor provided in the third chamber, and a permanent magnet provided on the rotor opposing the other side face of the impeller. A hydrodynamic groove is formed on the surface of the second barrier wall opposing the other side face of the impeller. The impeller separates from an inner wall of the second chamber and rotates in a non-contact state by the attractive force acting on one side face of the impeller from the electrical magnet, the attractive force acting on the other side face of the impeller from the permanent magnet of the rotor, and the hydrodynamic bearing effect of the hydrodynamic groove.
Additionally, the centrifugal blood pump of the Japanese Unexamined Patent Application Publication No. 2006-167173 (Patent Document 2) is provided with a housing including a first to a third chamber divided by first and second barrier walls, an impeller rotatably provided in the second chamber (blood chamber), a magnetic body provided on one side face of the impeller, a first permanent magnet provided in the first chamber opposing one side face of the impeller, a second permanent magnet provided on the other side face of the impeller, a rotor and a motor provided in the third chamber, and a third permanent magnet provided on the rotor opposing the other side face of the impeller. A first hydrodynamic groove is formed on the surface of the first barrier wall opposing one side face of the impeller, and a second hydrodynamic groove is formed on the surface of the second barrier wall opposing the other side face of the impeller. The impeller separates from the inner wall of the second chamber and rotates in a non-contact state by the attractive force acting on one side face of the impeller from the first permanent magnet, the attractive force acting on the other side face of the impeller from the third permanent magnet of the rotor, and the hydrodynamic bearing effect of the first and second hydrodynamic grooves.
Additionally, a turbo shaped pump in FIG. 8 and FIG. 9 of the Japanese Unexamined Patent Application Publication No. H4-91396 (Patent Document 3) is provided with a housing, an impeller rotatably provided in the housing, a first permanent magnet provided on one side face of the impeller, a rotor provided on an outer portion of the housing, a second permanent magnet provided on the rotor opposing the one side face of the impeller, a third permanent magnet provided on the other side face of the impeller, and a magnetic body provided on the housing opposing the other side face of the impeller. Additionally, the first hydrodynamic groove is formed on one side face of the impeller, and the second hydrodynamic groove is formed on other side face of the impeller. The impeller separates from the inside wall of the housing and rotates in a non-contact state by the attractive force acting on one side face of the impeller from the second permanent magnet of the rotor, the attractive force acting on the other side face of the impeller from the magnetic body of the housing, and the hydrodynamic bearing effect of the first and second hydrodynamic grooves.
Furthermore, a clean pump of the Japanese Unexamined Utility Model Application Publication No. H6-53790 (Patent Document 4) is provided with a casing, an impeller rotatably provided in the casing, a first permanent magnet provided on one side face of the impeller, a rotor provided on an outer portion of the casing, a second permanent magnet provided on the rotor opposing one side face of the impeller, a magnetic body provided on the other side face of the impeller, and an electrical magnet provided outside the housing opposing the other side face of the impeller. Additionally, the hydrodynamic groove is formed on one side face of the impeller.
When the rotational speed of the impeller is lower than a predetermined rotational speed, the electrical magnet activates, and when the rotational speed of the impeller exceeds a predetermined rotational speed, the power distribution to the electrical magnet is stopped. The impeller separates from the inside wall of the housing and rotates in a non-contact state by the attractive force acting on one side face of the impeller from the second permanent magnet of the rotor, and the hydrodynamic bearing effect of the hydrodynamic groove.